/*
	# Algorithm



	## Time Comlexity

	O(N)
*/

#include <stdio.h>
#include <algorithm>
#include <vector>
#include <unordered_map>

int main() {
	int n; scanf("%d", &n);
	std::vector<std::vector<int>> g(n);
	std::vector<int> a(n - 1), b(n - 1), c(n - 1);
	for(int i = 0; i < n - 1; i++) {
		scanf("%d%d%d", &a[i], &b[i], &c[i]); a[i]--; b[i]--;

		g[a[i]].push_back(i);
		g[b[i]].push_back(i);
	}

	std::vector<int> x(n), size(n); {
		auto dfs = [&](auto&& dfs, int v, int par, int xor_val) -> void {
			x[v] = xor_val;
			size[v] = 1;

			for(int id: g[v]) {
				int to = v ^ a[id] ^ b[id];
				if(to == par) continue;

				dfs(dfs, to, v, xor_val ^ c[id]);
				size[v] += size[to];
			}
		}; dfs(dfs, 0, -1, 0);
	}

	using i64 = long long;
	i64 ans = 0;

	std::vector<i64> count(n);
	std::unordered_map<int, i64> count_root; {
		std::unordered_map<int, int> map;
		for(int i = 0; i < n; i++) map[i] = -1;
		auto dfs = [&](auto&& dfs, int v, int par) -> void {
			if(map[x[v]] == -1) count_root[x[v]]++;
			else count[map[x[v]]]++;

			int prev = count[v];
			int tmp = map[x[v]]; map[x[v]] = v;
			for(int id: g[v]) {
				int to = a[id] ^ b[id] ^ v;
				if(to == par) continue;

				dfs(dfs, to, v);

				i64 diff = count[v] - prev; prev = count[v];
				ans += diff * (n - size[to]);
			}
			map[x[v]] = tmp;
		}; dfs(dfs, 0, -1);
	}
	{
		std::unordered_map<int, int> map;
		for(int i = 0; i < n; i++) map[i] = -1;
		auto dfs = [&](auto&& dfs, int v, int par) -> void {
			int root = map[x[v]];

			if(root == -1) ans += (count_root[x[v]] - 1) * size[v];
			else ans += count[root] * size[v];

			int tmp = map[x[v]]; map[x[v]] = v;
			for(int id: g[v]) {
				int to = v ^ a[id] ^ b[id];
				if(to == par) continue;

				dfs(dfs, to, v);
			}
			map[x[v]] = tmp;
		}; dfs(dfs, 0, -1);
	}

	ans = (i64)n * (n - 1) - ans;
	printf("%lld\n", ans);
}